Biomass fuel oven

ABSTRACT

A biomass fuel oven for use with biomass fuel granule. The oven has a body which is able to be levelly placed on the ground. The body has a combustion cabinet and an auxiliary equipment cabinet. The combustion cabinet has a burner received therein. The burner has a fire grate. A burning zone is defined beyond the fire grate and an air supply zone is defined below the fire grate. A plurality of air vents is defined in the fire grate. An air supply device is provided at the burning zone. The air supply device has a tubular inner wall and an air chamber surrounding the tubular inner wall. The air supply zone is in communication to the air chamber and is supplied air by an air blower via an air duct.

CROSS-REFERENCE TO RELATED APPLICATIONS

Not Applicable

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC

Not Applicable

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an oven for use with biomass fuel, and moreparticularly, to an oven using granule made by smashed and thenbriquetted straw, bits of wood, or crop stalks and having a turbulentflow air supply in a flame zone to highly increase a use ratio ofenergy.

2. Description of Related Art

Biomass fuel is granule made by smashed and then briquetted straw, bitsof wood, or crop stalks. As a new energy solution, biomass fuel haswider and wider been used because it is hygienic, environmental, highefficient, and economic.

A conventional biomass fuel oven is disclosed in a PCT patentapplication PCT/CN2012/01746 “A High Performance Oven” by thisapplicant. As shown in FIGS. 14 and 15, the oven has a body 9 having acombustion cabinet 91 and an auxiliary equipment cabinet 92. Thecombustion cabinet has a burner 93 received therein. The burner 93 has afire grate 931. A burning zone 932 is defined beyond the tire grate 931and an air supply zone 933 is defined below the fire grate 931. A flamezone 934 is above the burning zone 932 of the burner 93. An air supplydevice 94 is provided at the flame zone 934. The air supply device 94has a tubular inner wall 941, an enclosed air chamber 942, and an airduct 943 connecting the air chamber 942 and the air supply zone 933. Aplurality of deflecting devices 95 are longitudinally formed on thetubular inner wall 941 of the air supply device 94. Each deflectingdevice 95 has a long slit 951. On an outer surface of the tubular innerwall 941, a deflector 952 are formed all on a same side, left or right,of the long slits 951. Each deflector 952 extends towards correspondinglong slit 951 and having an angle with respect to the outer surface ofthe tubular wall 941. The angle is between 0 and 90 degree.

The aforementioned way of air supplying resolves the problem of airinterference between flows from each deflecting device, but the ovenstill has technical drawbacks. The deflecting device 95 forms an airflow going spirally upward like a tornado in the flame zone 934 in thetubular wall 941 of the air supply device 94. The spiral air flowresolves the interference between flows of supplying air and providesoxygen for combustion. However, just because of the unidirectionality ofthe flow of the supplying air, the oxygen in the supplying air is notable to completely mix with a burning gas, which results in anincomplete burning. Secondly, also because of the unidirectionality ofthe flow, without any impediment, an upgoing velocity of flow will bequick, which will quickly take away heat and some incompletely burn gas.This will bring further waste of energy. Third, since the incompleteburning caused by above two reasons, a carbon granule density of theincomplete burning gas of the waste gas will be high. An outwardphenomena is thick smoke. Forth, heat in the flame zone 934 in the airsupply device 94 is always being taken away quickly and no hightemperature is able to be produced.

Furthermore, for conventional biomass fuel ovens, form of the flames inthe hearth 91 is relatively disperse and not controllable. It isdifficult to concentrate the flames to increase a use ratio of heatenergy.

BRIEF SUMMARY OF THE INVENTION

The main object of the invention is to provide a biomass fuel oven whichis able to avoid interference between supplying air flows, and at thesame time, to completely mix oxygen in the supplying air with burninggas to make a fuller combustion.

Another object of the invention is to provide a biomass fuel oven whichis able to slow down an upgoing velocity of the burning gas in the flamezone to achieve a higher temperature for heating.

In order to accomplish the above objects, the present invention providesa biomass fuel oven for use with biomass fuel granule. The oven has abody which is able to be levelly placed on the ground. The body has atop panel and a side panel extending downward to the ground from the toppanel. The body further has a combustion cabinet and an auxiliaryequipment cabinet. The combustion cabinet has a burner received therein.The burner has a fire grate. A burning zone is defined beyond the firegrate and an air supply zone is defined below the fire grate. Aplurality of air vents is defined in the fire grate. An air supplydevice is provided at the burning zone. The air supply device has atubular inner wall and an air chamber surrounding the tubular innerwall. The air supply zone is in communication to the air chamber and issupplied air by an air blower via an air duct, the auxiliary equipmentcabinet has an electrical equipment received therein. The electricalequipment has the air blower, a power supply, and a switch. At least onerow of clockwise deflecting devices and at least one row ofanticlockwise deflecting devices are formed on the tubular inner wall ofthe air supply device.

The beneficiary effects of the invention are as follows. The air flowsentering into the flame zone respectively from the clockwise andanticlockwise deflecting devices are able to fully mix oxygen in thesupplying air with burning gas, which makes a more complete combustionand increases use ratio of energy. At the same time, compared with theconventional single spiral air flow, an interference between the twocountering air flows decrease an up-going velocity of high temperatureof burning gas. A longer lingering time in the flame zone of the burninggas will be able to obtain a higher burning temperature. In testingexperiments, the oven of the invention is able to increase temperatureby 20-30 percent compared to conventional biomass fuel ovens. Thirdly,because of the complete combustion, a density of carbon granule in thewaste gas decrease greatly. There is no more black smoke produced fromflames.

These and other objectives, features, and advantages of the presentinvention will become apparent from the following detailed description,the accompanying drawings, and the appended claims.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a schematic perspective view of the preferred embodiment ofthe invention.

FIG. 2 is an exploded perspective view of the oven shown in FIG. 1.

FIG. 3 a is a top plane view of a the oven shown in FIG. 1.

FIG. 3 b is a cross-sectional view along direction A-A shown in FIG. 3a.

FIG. 4 is a perspective partial view of a burner and an tubular innerwall of an air supply device.

FIG. 5 is a top plane view of the burner and the tubular inner wall ofthe air supply device.

FIG. 6 is a circuit diagram of an electrical equipment of the oven shownin FIG. 1.

FIG. 7 is a schematic perspective view of another embodiment of theinvention.

FIG. 8 is an exploded perspective view of the oven shown in FIG. 7.

FIG. 9 is a cross-sectional plane view of the oven shown in FIG. 7.

FIG. 10 is an enlarged perspective partial view of the air supply deviceshown in FIG. 7.

FIG. 11 is an enlarged plane partial view of the tubular inner wallshown in FIG. 10.

FIG. 12 is a circuit diagram of an electrical equipment of the ovenshown in FIG. 7.

FIG. 13 a through 13 c are enlarged perspective view of three other airsupply devices of the invention.

FIG. 14 is a cross-sectional plane view of a conventional biomass fueloven having air supply device. And,

FIG. 15 is an enlarged plane view of a tubular inner wall of the airsupply device shown in FIG. 14.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a schematic perspective view of the preferred embodiment of abiomass fuel oven of the invention. The oven has a body 1 which is ableto be levelly placed on the ground. The body 1 has a top panel 11 and aside panel 12 extending downward to the ground from the top panel 11.The body 1 has a combustion cabinet 10 and an auxiliary equipmentcabinet 20 received therein.

Together with reference to FIGS. 3 a and 3 b, the combustion cabinet 10has a burner 30 and an air supply device 40 received therein. The burner30 has a fire grate 31. A burning zone 32 is defined beyond the firegrate 31 and an air supply zone 33 is defined below the fire grate 31. Aplurality of air vents 311 are defined in the fire grate 31. The airsupply device 40 has a tubular inner wall 41 and an air chamber 42surrounding the tubular inner wall 41. In this embodiment, the airsupply zone 33 is in communication to the air chamber 42, and beingsupplied air by an air blower 51 via an air duct 34. The tubular innerwall 41 defines a flame zone 35 therewithin by the wall thereof.

Together with reference to FIGS. 4 and 5, at least one row of clockwisedeflecting devices 43 and at least one row of anticlockwise deflectingdevices 44 are formed on the tubular inner wall 41. Each row ofclockwise deflecting devices 43 has a plurality of first slit 431. On anouter surface of the tubular inner wall 41, a plurality of firstdeflectors 432 is respectively formed on one same side, left or right,of the first slits 431. Each first deflector 432 extends towardscorresponding first slit 431 and having an angle “a” with respect to anouter surface of the tubular wall 41. Angle “a” is between 0 and 90degree, preferably 45 degree. In the shown embodiment, all firstdeflectors 432 are on the left side of corresponding first slit 431 andextend towards corresponding first slit 431, i.e., towards right. Eachrow of anticlockwise deflecting devices 44 has a plurality of secondslit 441. On the outer surface of the tubular inner wall 41, a pluralityof second deflectors 442 is respectively formed on one same sidedifferent from the side of the first deflectors 432 of the second slits441. Each second deflector 442 extends towards corresponding second slit441 and having an angle “b” with respect to an outer surface of thetubular wall 41. Angle “b” is between 0 and 90 degree, preferably 45degree. In the shown embodiment, all second deflectors 442 are on theright side of corresponding second slit 441 and extend towardscorresponding second slit 441, i.e., towards left.

In the shown embodiment, the auxiliary equipment cabinet 20 has anelectrical equipment 50 received therein. The electrical equipment 50,as shown in FIG. 6, has the air blower 51 for supplying air to the airsupply zone 33 of the burner 30 and the air chamber 42, a power supply52, a switch 53 and a power light 54. The power supply 52 may be anindependent alternating current/direct current power supply 521, havingor having not a storage battery 522 in parallel as auxiliary. Either thealternating current/direct current power supply 521 or the storagebattery 522 is able to supply power independently. The switch 53 isinstalled on the side panel 12 and able to control the power supply ofwhole circuit. The power light 54 is also installed on the side panel 12near the switch 53 and used to indict status of power supply.

Fuel 70 is biomass fuel granule made by smashed and then briquettedstraw, bits of wood, or crop stalks.

In use, a user is able to first stably place the body 1 of the oven onthe ground where is desirable and then load fuel 70 onto the fire grate31 of the burner 30 through the flame zone 35 defined by the tubularinner wall 41 of the air supply device 40 in the combustion cabinet 10.When the user turns on the switch 53, the power light 54 turns up, whichmeans the electrical circuit is closed and the oven starts to work. Atthis time, the user is able to ignite the fuel 70 by throwing a burningalcohol cotton ball onto the fuel 70 on the fire grate 31. Also at thistime, the air blower 51 start to supply air to the air supply zone 33and the air chamber 42. Air entering the air supply zone 33 through theair vents 311 in the fire grate 31 provides oxygen for combustion of thefuel 70 in the burning zone 32. Air entering the air chamber 42 goesinto the flame zone 35 defined by the tubular inner wall 41 through allclockwise deflecting devices 43 and all anticlockwise deflecting devices44. Methane gas is created in a process of burning of the fuel 70. Withair flow produced by the air blower 51, the methane gas burns intoflames. Different to the conventional way of air supplying to the flamezone 35, air entering the flame zone 35 through each clockwisedeflecting device 43 unidirectionally flows clockwise after passing byeach first deflector 432. Therefore, the air in the flame zone 35 fromthe clockwise deflecting device 43 is in a form of unidirectionalspiral. At the same time, air entering the flame zone 35 through eachanticlockwise deflecting device 44 unidirectionally flows anticlockwiseafter passing by each second deflector 442. Therefore, the air in theflame zone 35 from the anticlockwise deflecting device 44 is in a formof unidirectional spiral opposite to the air flow from the clockwisedeflecting device 43. The air flows entering into the flame zone 35respectively from the clockwise and anticlockwise deflecting devices 43and 44 are able to fully mix oxygen in the supplying air with burninggas, which makes a more complete combustion and increases use ratio ofenergy. At the same time, compared with the conventional single spiralair flow, an interference between the two countering air flows decreasean up-going velocity of high temperature of burning gas. A longerlingering time in the flame zone 35 of the burning gas will be able toobtain a higher burning temperature. In testing experiments, the oven ofthe invention is able to increase temperature by 20-30 percent comparedto conventional biomass fuel ovens.

The tubular inner wall 41 may further has a plurality of turbulent airsupplier 45 defined therein. The turbulent air supplier 45 may be anymechanism which is able to supply air to the flame zone 35 in thetubular inner wall 41. As shown in FIG. 4, the embodiment of theturbulent air supplier 45 has a plurality of turbulent holes 451 definedin the tubular inner wall 41. After the air blower 51 is turned on,supplying air enters into the flame zone 35 defined by the tubular innerwall 41 not only through the clockwise and the anticlockwise deflectingdevices 43 and 44, but also through the turbulent holes 451 of theturbulent air supplier 45. The air flows entering into the flame zone 35through the turbulent air supplier 45 are able to further mix up oxygenin the supplying air and the burning gas and further increase the useratio of energy. At the same time, the air flows entering into the flamezone 35 through the turbulent air supplier 45 are able to furtherdecrease the up-going velocity of the burning gas, thus further increasethe temperature of the burning in the oven. Shown in FIGS. 13 a, 13 band 13 c are three other embodiments of the turbulent air supplier 45.In the embodiment shown in FIG. 13 a, the turbulent air supplier 45 is athin tube 452 in communication to the air chamber 42 and having aplurality of turbulent holes 451′ defined therein. In the embodimentshown in FIG. 13 b, the turbulent air supplier 45 is a plurality of thintubes 453 extending into the tubular inner wall 41 and having turbulentholes 451″ at free ends thereof. In the embodiment shown in FIG. 13 c,the turbulent air supplier 45 is two thin tubes 454 in communication tothe air chamber 42 extending into the tubular inner wall 41 and being incommunication to a circular thin pipe 455 having a plurality ofturbulent holes 451′″.

Shown in FIGS. 7, 8 and 9 is another embodiment of the invention.Compared with the preferred embodiment, the air supply zone 33 of theburner 30 in this embodiment is not directly in communication to the airchamber 42 of the air supply device 40. The air supply zone 33 and theair chamber 42 are respectively in communication to the air blower 51. Asecond difference is that besides the electrical equipment 50, theauxiliary equipment cabinet 20 further has a fuel supply mechanism 60received therein. The fuel supply mechanism 60 has a hopper 61 having alower outlet 611, a fuel tube 62 having one end in communication to thelower outlet 611 of the hopper 61 and a free end extending into theburning zone 32, and a rotary vane feeder 63 rotatably received in thefuel tube 62. The electrical equipment 50, as shown in FIG. 12, has theair blower 51 for supplying air to the air supply zone 33 of the burner30 and the air chamber 42, a power supply 52, a switch 53, a power light54, and a feeding motor 55 for driving the rotary vane feeder 63. Theswitch 53 is installed on the side panel 12 and able to control thepower supply of whole circuit. The power light 54 is also installed onthe side panel 12 near the switch 53 and used to indict status of powersupply. A door 121 is able to be provided in the side panel 12.

A shape of the tubular inner wall 41 does not have to be strictlytubular having a single diameter as shown in the preferred embodimentbut be able to be any shape which is basically a round tube such as atube having wave or a complex shape as an inner tube of a washingmachine, as shown in FIGS. 10 and 11. The tubular inner wall 41 shown inFIG. 7 has a shape of cone having a diameter of end being greater than adiameter of the other end. Also in the embodiment shown in FIG. 7, allthe first and the second slits 431 and 441 of the clockwise and theanticlockwise deflecting devices 43 and 44 are a thin slit having anangle “c” with respect to a generatrix “g” of the tubular inner wall 41.Angle “c” is between 0 and 45 degree, preferably 15 degree.

When the user needs to stop the burning, he is able to turn off theswitch 64, and the power light 65 goes out. The feeding motor 61 stopsrotating, and the air blower 62 ceases. As there is no new supply offuel 70, the fuel 70 in the burning zone 32 will burn up in a very shorttime period. The user then is able to open the door 121 and collect ashin the air supply zone 33. Outer region of the fire grate 31 may beoblique upward in a certain degree in order to form a centraldepression. The central depression is useful to gather fuel together toavoid black smoke caused by insufficient burning of the outer regionfuel 70.

From above description, it is seen that the objects of the presentinvention have been fully and effectively accomplished. Embodiment ofthe invention has been shown and described for the purposes ofillustrating the functional and structural principles of the presentinvention and is subject to change without departure from theinvention's principles. Therefore, this invention includes allmodifications encompassed within the spirit and scope of the followingclaims.

1. A biomass fuel oven for use with biomass fuel (70) granule andcomprising: a body (1) which is able to be levelly placed on the ground,said body (1) having a top panel (11) and a side panel (12) extendingdownward to the ground from said top panel (11) and having a combustioncabinet (10) and an auxiliary equipment cabinet (20), said combustioncabinet (10) having a burner (30) received therein, said burner (30)having a fire grate (31), a burning zone (32) being defined beyond saidfire grate (31), an air supply zone (33) being defined below said firegrate (31), a plurality of air vents (311) being defined in said firegrate (31), an air supply device (40) being provided at said burningzone (32), said air supply device (40) having a tubular inner wall (41)and an air chamber (42) surrounding said tubular inner wall (41), saidair supply zone (33) being in communication to said air chamber (42) andbeing supplied air by an air blower (51) via an air duct (34), saidauxiliary equipment cabinet (20) having an electrical equipment (50)received therein, said electrical equipment (50) having said air blower(51), a power supply (52), and a switch (53), at least one row ofclockwise deflecting devices (43) and at least one row of anticlockwisedeflecting devices (44) are formed on said tubular inner wall (41) ofsaid air supply device (40).
 2. The biomass fuel oven as claimed inclaim 1, wherein each row of said clockwise deflecting devices (43) hasa plurality of first slit (431), on an outer surface of said tubularinner wall (41), a plurality of first deflectors (432) beingrespectively formed on one same side of said first slits (431), eachsaid first deflector (432) extends towards corresponding said first slit(431) and having an angle “a” with respect to an outer surface of saidtubular wall (41), angle “a” being between 0 and 90 degree, and each rowof said anticlockwise deflecting devices (44) has a plurality of secondslit (441), on said outer surface of said tubular inner wall (41), aplurality of second deflectors (442) being respectively formed on onesame side different from said side of said first deflectors (432) ofsaid second slits (441), each said second deflector (442) extendstowards corresponding said second slit (441) and having an angle “b”with respect to said outer surface of the tubular wall, angle “b” beingbetween 0 and 90 degree.
 3. The biomass fuel oven as claimed in claim 1,wherein said tubular inner wall (41) further has a plurality ofturbulent air supplier (45) defined therein.
 4. The biomass fuel oven asclaimed in claim 2, wherein said tubular inner wall (41) further has aplurality of turbulent air supplier (45) defined therein.
 5. The biomassfuel oven as claimed in claim 3, wherein said turbulent air supplier(45) has a plurality of turbulent holes (451) defined in said tubularinner wall (41).
 6. The biomass fuel oven as claimed in claim 4, whereinsaid turbulent air supplier (45) has a plurality of turbulent holes(451) defined in said tubular inner wall (41).
 7. The biomass fuel ovenas claimed in claim 3, wherein said turbulent air supplier (45) is athin tube (452) in communication to said air chamber (42) and having aplurality of turbulent holes (451′) defined therein.
 8. The biomass fueloven as claimed in claim 4, wherein said turbulent air supplier (45) isa thin tube (452) in communication to said air chamber (42) and having aplurality of turbulent holes (451′) defined therein.
 9. The biomass fueloven as claimed in claim 3, wherein said turbulent air supplier (45) isa plurality of thin tubes (453) extending into said tubular inner wall(41) and having turbulent holes (451″) at free ends thereof.
 10. Thebiomass fuel oven as claimed in claim 4, wherein said turbulent airsupplier (45) is a plurality of thin tubes (453) extending into saidtubular inner wall (41) and having turbulent holes (451″) at free endsthereof.
 11. The biomass fuel oven as claimed in claim 3, wherein saidturbulent air supplier (45) is two thin tubes (454) in communication tosaid air chamber (42) extending into said tubular inner wall (41) andbeing in communication to a circular thin pipe (455) having a pluralityof turbulent holes (451′″).
 12. The biomass fuel oven as claimed inclaim 4, wherein said turbulent air supplier (45) is two thin tubes(454) in communication to said air chamber (42) extending into saidtubular inner wall (41) and being in communication to a circular thinpipe (455) having a plurality of turbulent holes (451′″).
 13. A biomassfuel oven for use with biomass fuel (70) granule and comprising: a body(1) which is able to be levelly placed on the ground, said body (1)having a top panel (11) and a side panel (12) extending downward to theground from the top panel (11) and having a combustion cabinet (10) andan auxiliary equipment cabinet (20), said combustion cabinet (10) havinga burner (30) received therein, said burner (30) having a fire grate(31), a burning zone (32) being defined beyond said fire grate (31), anair supply zone (33) being defined below said fire grate (31), aplurality of air vents (311) being defined in said fire grate (31), anair supply device (40) being provided at said burning zone (32), saidair supply device (40) having a tubular inner wall (41) and an airchamber (42) surrounding said tubular inner wall (41), said air supplyzone (33) and said air chamber (42) being respectively in communicationto said air blower (51), said auxiliary equipment cabinet (20) having anelectrical equipment (50) and a fuel supply mechanism (60) receivedtherein, said fuel supply mechanism (60) has a hopper (61) having alower outlet (611), a fuel tube (62) having one end in communication tosaid lower outlet (611) of said hopper (61) and a free end extendinginto said burning zone (32), and a rotary vane feeder 63 rotatablyreceived in said fuel tube (62), said electrical equipment (50) havingsaid air blower (51), a power supply (52), and a switch (53), at leastone row of clockwise deflecting devices (43) and at least one row ofanticlockwise deflecting devices (44) are formed on the tubular innerwall (41) of the air supply device (40).
 14. The biomass fuel oven asclaimed in claim 13, wherein each row of said clockwise deflectingdevices (43) has a plurality of first slit (431), on an outer surface ofsaid tubular inner wall (41), a plurality of first deflectors (432)being respectively formed on one same side of said first slits (431),each said first deflector (432) extends towards corresponding said firstslit (431) and having an angle “a” with respect to an outer surface ofsaid tubular wall (41), angle “a” being between 0 and 90 degree, andeach row of said anticlockwise deflecting devices (44) has a pluralityof second slit (441), on said outer surface of said tubular inner wall(41), a plurality of second deflectors (442) being respectively formedon one same side different from said side of said first deflectors (432)of said second slits (441), each said second deflector (442) extendstowards corresponding said second slit (441) and having an angle “b”with respect to said outer surface of the tubular wall, angle “b” beingbetween 0 and 90 degree.
 15. The biomass fuel oven as claimed in claim13, wherein said tubular inner wall (41) further has a plurality ofturbulent air supplier (45) defined therein.
 16. The biomass fuel ovenas claimed in claim 14, wherein said tubular inner wall (41) further hasa plurality of turbulent air supplier (45) defined therein.
 17. Thebiomass fuel oven as claimed in claim 15, wherein said turbulent airsupplier (45) has a plurality of turbulent holes (451) defined in saidtubular inner wall (41).
 18. The biomass fuel oven as claimed in claim16, wherein said turbulent air supplier (45) has a plurality ofturbulent holes (451) defined in said tubular inner wall (41).
 19. Thebiomass fuel oven as claimed in claim 15, wherein said turbulent airsupplier (45) is a thin tube (452) in communication to said air chamber(42) and having a plurality of turbulent holes (451′) defined therein.20. The biomass fuel oven as claimed in claim 16, wherein said turbulentair supplier (45) is a thin tube (452) in communication to said airchamber (42) and having a plurality of turbulent holes (451′) definedtherein.
 21. The biomass fuel oven as claimed in claim 15, wherein saidturbulent air supplier (45) is a plurality of thin tubes (453) extendinginto said tubular inner wall (41) and having turbulent holes (451″) atfree ends thereof.
 22. The biomass fuel oven as claimed in claim 16,wherein said turbulent air supplier (45) is a plurality of thin tubes(453) extending into said tubular inner wall (41) and having turbulentholes (451″) at free ends thereof.
 23. The biomass fuel oven as claimedin claim 15, wherein said turbulent air supplier (45) is two thin tubes(454) in communication to said air chamber (42) extending into saidtubular inner wall (41) and being in communication to a circular thinpipe (455) having a plurality of turbulent holes (451′″).
 24. Thebiomass fuel oven as claimed in claim 16, wherein said turbulent airsupplier (45) is two thin tubes (454) in communication to said airchamber (42) extending into said tubular inner wall (41) and being incommunication to a circular thin pipe (455) having a plurality ofturbulent holes (451′″).